1. Field of the Invention
This invention relates to lightweight aircraft transparencies and, in particular, to an antilacerative shield for an impact resistant aircraft windshield.
2. Technical Considerations
Windshields in aircraft applications must be resistant to weathering, scratching and high impact. A glass windshield can provide adequate weathering and scratch resistance, but glass plies may shatter upon impact. In order for a glass sheet to afford sufficient protection against shattering upon high impact, it would require a glass thickness that would be unacceptably heavy and optically inferior to the type of vision panel required for an aircraft windshield. As an alternative, thinner glass plies can be used in combination with lighter weight material plies such as polycarbonates or acrylic resins to provide a windshield that is lightweight, scratch and weather resistant and impact resistant. These glass/plastic composites generally include layers of flexible, compressible material interposed between adjacent glass and plastic layers to help bond the unit together. If the bonding between the glass and plastic is adequate, glass shards resulting from impact will remain adhered to the plastic rather than separate from the unit and inflict injury.